Aero Commander 500A accident near Livermore, California, May 20, 1994
On May 20, 1994, a Aero Commander 500A, registered N601MK, was destroyed in an accident near Livermore, California. It was a personal flight under general aviation rules (Part 91). 4 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A FUEL SYSTEM LEAK, INADEQUATE PREFLIGHT BY THE PILOT (PIC), AND BY THE NON-FLYING PILOT/PASSENGER INTENTIONALLY ALLOWING OPERATION OF THE AIRCRAFT WITH A KNOWN DEFICIENCY (FUEL LEAK). A FACTOR RELATED TO THE ACCIDENT WAS: THE LACK OF SUITABLE TERRAIN FOR A FORCED LANDING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 20, 1994
- Place
- Livermore, California · map
- Type
- Accident
- Injuries
- 4 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Aero Commander 500A · all 500As on the register
- Registration
- N601MK · registry record · serial 500A-1073
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRCRAFT HAD NOT FLOWN FOR 2 YEARS. BEFORE FLIGHT, A MECHANIC SAW EVIDENCE OF FUEL LEAKING AT DRAIN HOLES IN THE LEFT WING ROOT, JUST AFT OF THE MAIN CABIN DOOR. HE BROUGHT THIS TO THE ATTENTION OF THE PILOT-RATED PASSENGER, WHO SHORTLY THEREAFTER, DEPARTED IN THE AIRCRAFT WITH THE PILOT (PIC), THE AIRCRAFT OWNER & A PASSENGER/MECHANIC. ABOUT 14 MINUTES AFTER TAKEOFF, RADAR DATA SHOWED THE AIRCRAFT TRANSITIONING FROM A CLIMB TO A DESCENT, WHILE IN A 180 DEGREE TURN. ALSO, WITNESSES SAW SMOKE/FLAMES TRAILING FROM THE AIRCRAFT. SUBSEQUENTLY, THE AIRCRAFT IMPACTED TREES & POWER LINES, THEN IT CRASHED IN A SMALL FLAT FIELD IN HILLY TERRAIN. POST-CRASH EXAMINATION REVEALED MELTED ALUMINUM SPATTERS ON THE LEADING EDGE & UNDERSIDE OF THE LEFT HORIZONTAL STABILIZER. ALSO, 'FOCALIZED' FIRE DAMAGE WAS NOTED ON THE CABIN BEHIND THE DRAIN HOLES IN THE LEFT WING ROOT. TETRAHYDROCANNABINOL CARBOXYLIC ACID (MARIJUANA) WAS DETECTED IN THE PILOT-RATED PASSENGER'S BLOOD (0.004 UG/ML) & URINE (0.010 UG/ML).
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 23,700 hours in all
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 6,250 lb
- Seats: 7
- Landing gear: retractable
- Engine: Continental IO-470-M (piston); 0 hours total
The flight
- Departed from: HWD Hayward CA
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 230° at 8 knots
- Visibility: 25 statute miles
- Sky: broken clouds at 5,000 ft; scat at 3,500 ft
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.